Iridomyrmex atypicus, Heterick & Shattuck, 2011

Heterick, Brian E. & Shattuck, Steve, 2011, Revision of the ant genus Iridomyrmex (Hymenoptera: Formicidae) 2845, Zootaxa 2845 (1), pp. 1-174 : 47-48

Iridomyrmex atypicus sp. n.

( Fig. 14 )

Types. Holotype worker from 40km NNW Louth ( Lake Mere ), New South Wales, 30 October 1986, P. J. M. Greenslade ( ANIC, ANIC32-032735 ) . Paratypes: 2 workers from CSIRO Lake Field stn. near Louth , New South Wales, January 1995, M. Bryannah ( ANIC, ANIC32-036481 , 1 worker; MCZC, ANIC32-036482 , 1 worker) .

Worker Description. Head. Posterior margin of head planar to weakly concave; erect setae on posterior margin in full-face view set in a row; sides of head noticeably convex; erect genal setae present on sides of head in fullface view, or absent from sides of head in full-face view (one to a few small setae may be present near mandibular insertion). Ocelli absent; in full-face view, eyes set at about midpoint of head capsule; in profile, eye set anteriad of head capsule; eye semi-circular. Frontal carinae convex; antennal scape surpassing posterior margin of head by 1–2 x its diameter. Erect setae on scape absent, except at tip; prominence on anteromedial clypeal margin projecting as triangular spur; mandible elongate triangular with oblique basal margin; long, curved setae on venter of head capsule absent. Mesosoma. Pronotum moderately and evenly curved over its length. Erect pronotal setae moderate in number (6–12), short and bristly. Mesonotum evenly curved. Erect mesonotal setae moderate in number (6–12), short and bristly. Mesothoracic spiracles always inconspicuous; propodeal dorsum smoothly and evenly convex; placement of propodeal spiracle mesad, more than its diameter away from propodeal declivity; propodeal angle weakly present or absent, the confluence of the dorsal and declivitous propodeal faces indicated, if at all, by an undulation. Erect propodeal setae moderate in number (6-12), short and bristly. Petiole. Dorsum of node convex; node thin, scale-like, orientation more-or-less vertical. Gaster. Non-marginal erect setae of gaster present on first gastral tergite; marginal erect setae of gaster present on first tergite. General characters. Allometric differences between workers of same nest absent. Colour dull brown, lighter around clypeus and lower genae. Colour of erect setae yellowish.

Measurements. Worker (n = 1)—CI 78; EI 32; EL 0.26; EW 0.21; HFL 1.14; HL 1.02; HW 0.80; ML 1.20; MTL 0.81; PpH 0.14; PpL 0.48; SI 100; SL 0.80.

Comments. Large, almost circular eyes, a relatively short antennal scape and a somewhat elongate head ensure that I. atypicus cannot be confused with any other Iridomyrmex . This taxon appears to have an oddly circumscribed distribution, with the only known specimens coming from near Lake Mere, New South Wales. Nothing further is known of this rare species.

Etymology. Latin: named for the highly distinctive nature of its appearance.

Figures

FIGURE 14. Iridomyrmex atypicus (holotype, Louth, Lake Mere, NSW, ANIC32-032735): A. Front of head; B. Side of body; C. Top of body; D. Distribution of material examined.